/**
* Copyright (c) 2010 Yahoo! Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you
* may not use this file except in compliance with the License. You
* may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing
* permissions and limitations under the License. See accompanying
* LICENSE file.
*/
package com.yahoo.ycsb.generator;
import java.util.Vector;
/**
* An expression that generates a random integer in the specified range
*/
public class UniformGenerator extends Generator
{
Vector<String> _values;
String _laststring;
UniformIntegerGenerator _gen;
/**
* Creates a generator that will return strings from the specified set uniformly randomly
*/
@SuppressWarnings( "unchecked" )
public UniformGenerator(Vector<String> values)
{
_values=(Vector<String>)values.clone();
_laststring=null;
_gen=new UniformIntegerGenerator(0,values.size()-1);
}
/**
* Generate the next string in the distribution.
*/
public String nextString()
{
_laststring=_values.elementAt(_gen.nextInt());
return _laststring;
}
/**
* Return the previous string generated by the distribution; e.g., returned from the last nextString() call.
* Calling lastString() should not advance the distribution or have any side effects. If nextString() has not yet
* been called, lastString() should return something reasonable.
*/
public String lastString()
{
if (_laststring==null)
{
nextString();
}
return _laststring;
}
}